Automatic band polishing machine

ABSTRACT

A machine for polishing inside walls of a ring-shaped workpiece, such as handles of scissors and the like, in which the workpiece is automatically selected, set up in position and burnished by an endless belt, after which the workpiece is dropped and another workpiece selected. The machine includes a pair of spaced supports for the endless belt with the workpiece therebetween and performs the polishing operation automatically by pushing a loop of the belt through the workpiece opening, expanding the passedthrough loop, placing this expanded loop upon a pulley, and then rotating the belt, the spaced supports also being simultaneously rotated around its longitudinal axis and the workpiece position altered so as to enable all interior surfaces of the ring to be polished.

Tlnited States Patent [72] Inventor Ottorino Visconti 11, V. Carducci,Milan, Italy [21] Appl. No. 62,975 [22] Filed Aug. 11, 1970 [45]Patented Dec. 21, 1971 [32] Priority Sept. 16, 1969 [33] Italy [3 I]22087 A/69 [54] AUTOMATIC BANI) POLISHING MACHINE I1 Claims, 9 DrawingFigs.

[52] U.S.Cl 51/148, 51/290 [51] Int.Cl ..B24b211/l6 [50] Field oISearch51/135, 142, 148, 290

[56] References Cited UNITED STATES PATENTS 782,245 2/1905 Herrmann51/148 Primary Examiner-D0na1d G. Kelly Attorney-Leo C. KrazinskiABSTRACT: A machine for polishing inside walls of a ring shapedworkpiece, such as handles of scissors and the like, in which theworkpiece is automatically selected, set up in position and burnished byan endless belt, after which the workpiece is dropped and anotherworkpiece selected. The machine includes a pair of spaced supports forthe endless belt with the workpiece therebetween and performs thepolishing operation automatically by pushing a loop of the belt throughthe workpiece opening, expanding the passed-through loop, placing thisexpanded loop upon a pulley, and then rotating the belt, the spacedsupports also being simultaneously rotated around its longitudinal axisand the workpiece position altered so as to enable all interior surfacesof the ring to be polished.

PATENTEU nim SHEET 3 BF 5 AUTOMATIC BAND POLISHING MACHINE SUMMARY OFTHE INVENTION This invention relates' to an automatic band polishingmachine for burnishing the inside parts of ring shaped elements, oftoroidal, bow and long ring shapes, for example the rings of scissorhandles.

Until now, this burnishing operation has been effected manually byspecialized workmen with considerable loss of time. This type ofoperation is uneconomical and also injurious to the health of theworkmen who may inhale the abrasive dust generated during thisoperation.

It is accordingly an object of the invention to provide a machine whichenables automatic threading up of the polishing band so that theabove-mentioned operation can be carried out automatically with aconsiderable production per unit of time whilst reducing the number ofworkmen who are required only to control the machine and to load andunload the rough finished workpieces. The workmen need no longer besubject to the unhealthy inhalation of dust, since the requirement formanual access to the polishing band is avoided and the machine can beenclosed within a housing which incorporated therein a dust exhaustinginstallation the function of which is to stop the spreading of dust intothe plant.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I shows a perspectivediagrammatic view of a machine according to the invention,

FIG. la is a perspective view of part of the machine of FIG. I in thedirection of the arrow A,

FIGS. 2a, 2b, 2c show three diagrammatic longitudinal views of thepolishing band in three positions before beginning of work.

FIGS. 2d, 2e, 2f show three diagrammatic longitudinal views of thepolishing band on the idler pulley and during two following workingsteps, and

FIG. 3 shows a diagrammatic perspective view of a control devicecomprising a cam shaft and associated microswitches, and pneumaticcircuit.

DETAILED DESCRIPTION Referring to the drawings, FIG. 1 shows a frameworkwith a polishing band 1, having abrasive material such as emery on onesurface, in the idle position or during the exchange of workpieces Wresting upon a driving pulley 2 which is fixed to an electric motor 3mounted on a slide 4 which runs on appropriate guides 5 and which isspring loaded by a compression spring 6 in a direction away from theworkpiece W, i.e. to the left as viewed in the drawing. The guides 5 arefixed on a frame 7 in turn secured to a plate 15. On plate 15 arefastened by means of an appropriate support a pair of pins 8, formingfixed stops for positioning the band during the displacement caused by apair of tensioning arms 9, as described below. Each arm 9 is fixed atone end upon a fulcrum I1 and is loaded by a tension spring 12 (FIG.211). At the other extremity of each arm 9 is mounted a tensioningpulley for carrying the polishing band in constant tension.

The band 11, whilst stationary at the left side of FIG. 1 passes aroundthe driving pulley 2 and thence via the pins 8 and the pair of tensionpulleys 10 passes around the right side of a pusher 13. The pusher 13 ispositioned coaxially with the band, so that the band will be retainedthereon, and is reciprocated as required by a pneumatic cylinder 14rigidly secured to the frame 7.

All of the items mentioned, i.e., motor 3 with slide 4 and compressionspring 6, pins 8, tensioning arms 9 and the pusher 13 with its drivingcylinder 14 are mounted upon the frame 7 which can rotate together witha plate 15 supported by four idler wheels 16 and connected to a ringgear 17 in mesh with a pinion 18 mounted upon a countershaft 19 drivenby a motor 20. As a consequence of the above arrangement, the whole LIIframe 7 is able to rotate together with the associated parts about thelongitudinal axis of the machine simultaneously with the items mountedon the opposite side of the machine in relation to the workpiece W anddescribed hereinafter.

On the other side of the workpiece W that is, to the right of theworkpiece, as viewed in FIG. 1 there is shown a gear wheel 21 fixed uponappropriate bearings (not shown) and in mesh with a pinion 22 keyed onthe same countershaft I9 driven by the motor 20. A slide 23 is mountedto run radially upon guides 24 fixed on the gear wheel 21. The radialdisplacement of the slide 23 is controlled by a pneumatic cylinder 25fixed on the gear 21. The slide 23 carries two parallel brackets 26 and26' on which two holding plates 27 and 27' are displaceably mountedrespectively. These holding plates can be moved in a directionperpendicular to the rotary axis of the machine along two pairs ofguides 28 and 28' controlled by two pneumatic cylinders 29 and 29 fixedon the brackets 26 and 26. On the holding plate 27 is mounted an idlerpulley 30 the axis of which is perpendicular to the rotary axis of themachine. On the holding plate 27' is mounted a pair of fingers 31a and31b which-in the idle position-are located in front of the idler pulley30, parallel to and at a certain distance from it. These fingers 31a,31b are provided on a pair of levers 32a and 32b, respectively, pivotedon the holding plate 27 and controlled by a pneumatic cylinder 33 bymeans of a suitable linkage (see FIGS. 2ac). The movements anddimensions of the levers 32a and 32b are such that fingers 31a and 31bcan be introduced within the band 1 at both sides of the end of thepusher 13 and then spread apart to open out and extend the band 1 sothat the idler pulley 30 can be introduced within the band I asdescribed below.

Between the pusher l3 and the fingers 31a and 31b there is a magazine 34for the workpieces W. This magazine 34 can be of any type and maycomprise a frame within which a plurality of workpiece holders 35 can beadvanced stepwise by a pneumatic cylinder 36 and a pawl and ratchetmechanism, not shown, in order to locate the workpieces in a deliveryposition from which they can be received by a mechanism 41. Themechanism 411 is arranged on the opposite side of the rotary axis of themachine with respect to the magazine 34 and in alignment with thelatter.

The clamping mechanism 41 is of a conventional type used for mechanicalhandling and will not therefore be described in detail herein. In thisparticular case it comprises jaws 37 one of which is fixed to an arm 38and the other of which is movable to grip the workpiece W.

The arm 38 is the piston rod of a pneumatic cylinder 38' and moves toadvance the clamping jaws 37 for gripping the workpiece W as carriedforward by the magazine 34, and then to retract them to bring the workpieces into the working position. A pneumatic cylinder 39 with an axisperpendicular to the arm 38 tilts the workpiece during a particularworking step (FIG. 2f). If desired further similar means may be providedto impart any additional motions to the workpieces, for example to swingthem about an axis perpendicular to the rotary axis of the machine.

As shown in FIG. 3, the machine is provided with a control devicecomprising a cam shaft 42 carrying cam discs 42a and 42h. The cam shaft42 is driven by a motor 43 provided with a reduction gear (not shown)and connected to a power supply 44 by way of a timer 45. The cam discs42a-42h are arranged to actuate microswitches 46a-46h, which in turnactuate electrically operable air valves 47a-47h connected to an airsupply 48 and respectively actuating the corresponding cylinders 14, 29,33, 29, 38, 36, 25 and 39 The operation of the described machine is asfollows: referring to FIGS. 1 and 2a it can be seen that the polishingband I, in the idle position or when the workpiece W is being exchanged,rests upon the pulley 2, on the stops 8, on the tensioning pulleys 10and the tip of the pusher 13. The polishing band 1 is tensioned by apair of springs 12 which load the two lever-arms 9 carrying thetensioning pulleys 10 when advanced by the pusher I3 during its forwardstroke under control of the cylinder 14. When the timer 45 is set inoperation to activate motor 43, can shaft 42 is rotated and cam discs42a-h which in turn energize the electromagnetic valves 47a-h to powerthe cylinders 14, 29, 33, 29, 38', 36, 25 and 39. The first step of thecycle commences when the cam 42c actuates microswitch 460 to power thecylinder 36 so that a new workpiece W is advanced into the path of thepiston rod 38 from the magazine 34, and the cam 42d actuates microswitch46d to actuate power cylinder 38 and thus extend piston rod 38.Simultaneously, the mechanism 41 actuates the jaws 37 to clasp the nextworkpiece W in the magazine 34. The cam 42d then releases themicroswitch 46d and in turn cylinder 38, and the piston rod 38 thenmoves back stopping the new workpiece W in the necessary workingposition. The cam 420 also releases microswitch 46c so that cylinder 36returns to the idle position, the pawl and ratchet mechanism leaving themagazine 34 in the advanced position. The cam 42h now actuatesmicroswitch 46h, to power the cylinder 14 and extend the pusher 13 inthe forward direction. During this forward stroke of the pusher 13, anarrow loop of the band 1 is passed through a ring 40 of the workpieceW, which is located in the working position by the clamping mechanism41. After the displacement of the pusher 13, the cam 42g actuatesmicroswitch 46 g to power the pneumatic cylinder 29 so that the fingers31a, 31b are raised into the position shown in FIG. 2b, i.e. one on eachside of the pusher and inside the loop of the band 1 which is alreadyinside the workpiece. As soon as the loop of the band 1 is engaged bythe fingers 31a, 31b, the cam 42f actuates microswitch 46f to power thecylinder 33 which pivots the two levers 32a and 32b about theirfulcrums, so that the fingers 31a, 31b spread apart to open out the loopof the band 1. The cam 42c than actuates microswitch 46e to power thecylinder 29 so that the idler pulley 30 is then moved downwardly asviewed in FIG. 1 and lies within the widened loop of the band 1. Then,cam 42f releases microswitch 46f and cylinder 33 is returned to its idleposition so that the fingers 31a and 31b close the loop of the band 1,tensioned by the pair of spring loaded arms 9, can conform to the idlerpulley 30. The band can be drawn into the positions shown in FIGS. 20and 2d not only because of the taking up of the loops of the bandprovided by arms 9 but also because of the displacement of motor 3 andof slide 4 on the guides 5 against the compressive force of the spring6.

At the same time, cam 42h releases microswitch 46h so that cylinder 14moves pusher 13 back into its idle position and cam 42g releasesmicroswitch 46g and the cylinder 29' lowers fingers 31a and 3111, asviewed in FIG. 1, away from the rotary axis of the machine(FIG. 2d) sothat they do not obstruct movement of the band 1. Then the cam 42bactuates microswitch 46b so that the pneumatic cylinder 25 acts on theslide 23 and the pulley 30 moves away from the rotary axis of themachine and provides the band 2 with the cutting angle a which isnecessary to process the ring shaped part 40. (Drawing 2e). At the sametime cam 42a actuates microswitch 46a to power cylinder 39 so that thearm 38 is tilted about its axis to incline the workpiece at the angle [3during finishing, see FIG. 2f. Now the timer 45 is set to initiate thepolishing operation by means ofa cam 49 of the cam shaft and amicroswitch 50. First the motor 3 is activated by timer 45 to drive theband I by means of the driving pulley 2 and the polishing operationbegins, whereas the motor 43 is stopped by the timer 45 and the camshaft 42 also stops. At the same time the motor 20 is also activated bytimer 45, and the countershaft l9 and the two pinions 18 and 22, thering gear 17 and gear wheel 21 are driven so that the two units on bothsides of the workpiece W rotate in synchronism and the band 1 rotatesinside the ring shaped opening 40. Consequently the plane defined by theband 1 as driven by the driving pulley 2 and by the idler pulley 30rotates about the axis of the machine.

When the polishing operation is completed, after he time set by thetimer 45, the latter stops the motors 3 and 20 and starts the motor 43so that further steps of the cycle can be provided by the cam shaft 42.Thus the cam 42breleases the microswitch 46b so that the cylinder 25moves the pulley 30 back towards the rotary axis of the machine. The cam42a releases microswitch 46a so that cylinder 39 is returned to the idleposition (FIG. 1), the cam 42g actuates microswitch 46g to powercylinder 29 so that the fingers 31a, 31b are raised, as viewed in FIG.1, to the rotary axis of the machine and the cam 42f actuatesmicroswitch 46f to power cylinder 33 so that it reopens the fingers 31aand 31b as shown in FIG. 2c, hooking the two arms of the loop of theband 1 in order to remove it from the idler pulley 30. The cam 42e thenreleases microswitch 46c so that cylinder 29 returns to the positionshown in FIG. I and the idler pulley 30 is removed from the path of theband 1. The cam 42h then actuates microswitch 46h to power cylinder 14so that the pusher 13 is again advanced through the workpiece opening40.

The cam 42f then releases microswitch 46f to return the cylinder 33 andthe fingers 31a, 31b to the position shown in FIG. 2b, so that the band1 is laid upon the tip of the pusher 13 by fingers 31a and 31b. Duringthis movement, the band 1 will be constantly kept in tension by thespring 12 and the tensioning arms, and the spring 6 which tends to urgethe motor 3 to the left as viewed in the drawings. Immediatelyafterward, the cam 42g releases microswitch 46g and the cylinder 29'returns to the position of FIG. 1 to remove the fingers 31a, 31b fromthe path of the band 1. The cam 42h now releases microswitch 46h so thatthe cylinder 14 returns to the idle position thus withdrawing the pusherl3 and the band 1 back again through the workpiece opening 40 to theinitial idle position. The working cycle is now complete and the nextcycle can be commenced on a new workpiece. Upon extension of the pistonrod 38 to engage a new workpiece as described above, the mechanism 41releases the finished workpiece W so that it falls onto a delivery chutenot shown.

It should be understood that the machine described above illustrates oneexample only of the invention and alterations and modifications can bemade thereto without departing from the scope of the invention asdefined in the claims. For example, the cylinder 39 for inclining theworkpiece during working (Drawing 2f), for the working of scissors withinclined finger holes, may be replaced by any other suitable locatingmeans for the working of pieces with peculiar shapes, and devices forexample for the axial movement of the workpiece can be added, so thatall surfaces of the workpiece are conveniently positioned against theband 1 in turn.

As previously mentioned, the control and programming device can be ofany known type provided that it guarantees the necessary synchronismbetween the operation of the relevant parts of the machine and themotors and permits the regulation of the working times of the variousphases, and may comprise a completely electronic control circuit. Infact, the machine according to this invention could be used successivelyfor different working steps of a polishing process, or for differentworkpieces requiring a different type of abrasive.

Also, the machine can be constructed with a ditferent workpiece loadingand handling mechanism, for instance with a vertical magazine and/orwith a different clasp mechanism or magazine adapted to various types ofworkpieces, for example a plate-rack in which the workpieces are loadedand from which they are then removed by the clasp mechanism. Moreover,the driving cylinders can be hydraulic instead of pneumatic, theelectric motors can be equipped with variable speed control, and anymodification of structure, outsidev shape, control devices and auxiliarymechanisms can be carried out. In particular, instead of rotating theband 1 as a whole by means of the ring gear 17 and gear wheel 21, meansmay be provided for rotating the workpiece itself while the path of theband 1 remains fixed.

Iclaim:

I. A machine for the automatic polishing of the inside surfaces of ringshaped workpieces, said machine comprising two spaced supporting means,an endless polishing band carried by said supporting means, said bandbeing adapted to run thereon and between which the workpiece is intendedto be placed,

band tensioning means associated with one of said supporting means tosupport the endless band in an idle position free of the othersupporting means whereby the ring shaped workpiece can be positioned inthe free space between the endless band and said other supporting means,means for extending the endless band from its idle position through thering shaped workpiece so positioned towards said other supporting means,further means for receiving the extended portion of said endless bandand placing it around the said other supporting means, and means fordriving the endless band extending between the two supporting means topolish the workpiece.

2. A machine as claimed in claim ll, further comprising a support forreceiving the workpiece and means for imparting relative rotation tosaid support and the supporting means for the band, about a longitudinalaxis of the machine.

3. A machine as claimed in claim 2, in which the said band supportingmeans respectively comprise pulleys at least one of which is arranged tobe driven by said driving means, the said band extending meanscomprising a pusher member mounted for rectilinear movement within theperiphery of the band in order to engage and extend the band against theresistance of the tensioning means, and the said band receiving meanscomprising a plurality of fingers for insertion within the extendedportion of the band to open out the latter for arrangement over thecorresponding pulley.

4. A machine as claimed in claim 3, in which a driven one of saidpulleys together with the driving means therefor, the band tensioningmeans and the pusher member are mounted upon a common rotary member onone side of the workpiece support, and the other pulley, being an idlerpulley, and the band receiving means are mounted upon a further rotarymember coaxial with the first and arranged on the other side of theworkpiece support, means being provided for rotating said tow rotarymembers in synchronism in order to rotate the endless band relatively tothe workpiece about said longitudinal axis of the machine.

5. A machine as claimed in claim 4, in which the said plurality offingers and the pulley associated therewith are each mounted formovement along an axis perpendicular to the medial plane of the endlessband, and are so arranged for movement in timed relation that with theband extended by said pusher member, first the fingers are moved alongthe corresponding axis and inserted within the band, the fingers arethen spread apart to open out the band, the pulley is moved along itscorresponding axis and inserted within the opened out portion of theband, the fingers are then contracted together to allow the band toconform to the pulley and finally the fingers are withdrawn from theband by movement along the corresponding axis.

6. A machine as claimed in claim 5, in which the pulley associated withsaid fingers is also mounted for movement along a further axis at rightangles to the first in order to vary the cutting angle of the bandrelatively to a workpiece.

7. A machine as claimed in claim 6, in which the said band tensioningmeans comprises a pair of arms each pivoted at one end upon a commonsupport together with the associated band supporting means, and eachhaving an idler pulley for engagement with the band and being springloaded in a direction for tensioning the band.

8. A machine as claimed in claim 7, in which the said driving meanscomprises a motor with a band driving pulley fixed to the motor shaft,the motor being slidably mounted for movement at right angles to themotor axis and being spring loaded for sliding movement in a directionto tension the polishing band.

9. A machine as claimed in claim d, including a magazine device forfeeding workpieces consecutively to the working position, said devicebeing arranged to operate in timed relation to the said band extendingmeans so that workpieces are advanced to and from the working positionwhen the band is retracted, and the band extending and polishingoperations are effected between advancing ste s of'the feed device. I

ll machine as claimed in c arm 9, 1n WhlCh the said magazine feedingdevice comprises a magazine for workpieces arranged laterally adjacentthe path of the polishing band, and said workpiece support includes agripping device for workpieces arranged for to and fro movementtransversely to the path of the band to transfer workpieces from themagazine to the working position.

11. A machine as claimed in claim It), in which the said gripping deviceis further arranged for movement to vary the working position of theworkpiece during polishing.

1. A machine for the automatic polishing of the inside surfaces of ringshaped workpieces, said machine comprising two spaced supporting means,an endless polishing band carried by said supporting means, said bandbeing adapted to run thereon and between which the workpiece is intendedto be placed, band tensioning means associated with one of saidsupporting means to support the endless band in an idle position free ofthe other supporting means whereby the ring shaped workpiece can bepositioned in the free space between the endless band and said othersupporting means, means for extending the endless band from its idleposition through the ring shaped workpiece so positioned towards saidother supporting means, further means for receiving the extended portionof said endless band and placing it around the said other supportingmeans, and means for driving the endless band extending between the twosupporting means to polish the workpiece.
 2. A machine as claimed inclaim 1, further comprising a support for receiving the workpiece andmeans for imparting relative rotation to said support and the supportingmeans for the band, about a longitudinal axis of the machine.
 3. Amachine as claimed in claim 2, in which the said band supporting meansrespectively comprise pulleys at least one of which is arranged to bedriven by said driving means, the said band extending means comprising apusher member mounted for rectilinear movement within the periphery ofthe band in order to engage and extend the band against the resistanceof the tensioning means, and the said band receiving means comprising aplurality of fingers for insertion within the extended portion of theband to open out the latter for arrangement over the correspondingpulley.
 4. A machine as claimed in claim 3, in which a driven one ofsaid pulleys together with the driving means therefor, the bandtensioning means and the pusher member are mounted upon a common rotarymember on one side of the workpiece support, and the other pulley, beingan idler pulley, and the band receiving means are mounted upon a furtherrotary member coaxial with the first and arranged on the other side ofthe workpiece support, means being provided for rotating said tow rotarymembers in synchronism in order to rotate the endless band relatively tothe workpiece about said longitudinal axis of the machine.
 5. A machineas claimed in claim 4, in which the said plurality of fingers and thepulley associated therewith are each mounted for movement along an axisperpendicular to the medial plane of the endless band, and are soarranged for movement in timed relation that with the band extended bysaid pusher member, first the fingers are moved along the correspondingaxis and inserted within the band, the fingers are then spread apart toopen out the band, the pulley is moved along its corresponding axis andinserted within the opened out portion of the band, the fingers are thencontracted together to allow the band to conform to the pulley andfinally the fingers are withdrawn from the band by movement along thecorresponding axis.
 6. A machine as claimed in claim 5, in which thepulley associated with said fingers is also mounted for movement along afurther axis at right angles to the first in order to vary the cuttingangle of the band relatively to a workpiece.
 7. A machine as claimed inclaim 6, in which the said band tensioning means comprises a pair ofarms each pivoted at one end upon a common support together with theassociated band supporting means, and each having an idler pulley forengagement with the band and being spring loaded in a direction fortensioning the band.
 8. A machine as claimed in claim 7, in which thesaid driving means comprises a motor with a band driving pulley fixed tothe motor shaft, the motor being slidably mounted for movement at rightangles to the motor axis and being spring loaded for sliding movement ina direction to tension the polishing band.
 9. A machine as claimed inclaim 8, including a magazine device for feeding workpiecesconsecutively to the working position, said device being arranged tooperate in timed relation to the said band extending means so thatworkpieces are advanced to and from the working position when the bandis retracted, and the band extending and polishing operations areeffected between advancing steps of the feed device.
 10. A machine asclaimed in claim 9, in which the said magazine feeding device comprisesa magazine for workpieces arranged laterally adjacent the path of thepolishing band, and said workpiece support includes a gripping devicefor workpieces arranged for to and fro movement transversely to the pathof the band to transfer workpieces from the magazine to the workingposition.
 11. A machine as claimed in claim 10, in which the saidgripping device is further arranged for movement to vary the workingposition of the workpiece during polishing.